I have had the same problems with not being able to click anything at the menu for awhile. The way to fix it (at least temporarily) is to change the defaultbindings and keybindings to where the values look like this:

camera_move_forward = button-1attack = w

Now, I know that it doesn't sound like it will work, since the FAQ's say the opposite, but IT DOES!!!

Huh, okay. It could be that there's some other software interfering and causing some strange issues, and that somehow gets solved with this. Sounds very strange even so but that's life sometimes. I'm glad if it solved your problem though.